The disclosure relates to semiconductor memory devices, and more particularly, to a storage device and a method of operating the same.
A flash memory device is widely used as an audio and image data storage medium of information devices such as a computer, a PDA, a digital camera, a camcorder, a voice recorder, an MP3 player, a handled PC. However, an erase operation has to precede and write operation of data in a flash memory and there is a characteristic that a unit of data being erased is greater than a unit of data being written. In a case where a flash memory is used as an auxiliary memory device, this characteristic may become a factor that impedes a use of a file system for a general hard disk. This characteristic implies that a sequential input/output processing of a flash memory is more effective than a non-sequential input/output processing.
An SSD (solid state drive) is a typical example of a large capacity storage device based on a flash memory. With a huge increase in demand, a use for an SSD is variously divided. For example, a use for an SSD may be subdivided into an SSD for a server, an SSD for a client, an SSD for a data center, etc. An interface of an SSD has to provide an optimum speed and optimum reliability according to each kind of use. To satisfy these kinds of requirements, an SATA, a PCIe, an SAS, etc. are applied as an optimum SSD interface. A PCIe-based NVMe and a UFS-based UME (unified memory extension) are being actively studied and is being applied to storage devices these days. These interfaces provide a memory sharing function between devices. Thus, a data management method of storage using a sharing method of this memory resource has become desirable.